Communication system, communication device, and communication device management method

ABSTRACT

A communication system includes a control terminal device and one or more communication devices. The control terminal device transmits a search message to entire network when the communication device is registered into the communication system. When the communication device is connected to the network, the communication device determines whether a connection position of the connected communication device on the network is the predetermined connection position. When the communication device is not positioned at the predetermined connection position, the communication device cancels the connection with the network and then connects to the predetermined connection position of the network and responds to the search message through the network after the communication device directly connects to the control terminal device and obtains information for connecting to the predetermined connection position of the network.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 15/805,541, filed on Nov. 7, 2017, which is a continuation of PCTapplication No. PCT/JP2016/074194, which was filed on Aug. 19, 2016based on Japanese Patent Application (No. 2015-162329) filed on Aug. 19,2015, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

This disclosure relates to an audio system (communication system) wherea plurality of audio devices (communication devices) are connected by anetwork.

2. Description of the Related Art

In audio systems formed of a plurality of audio devices, conventionally,audio devices are connected together by an analog or a digital audiocable. In recent years, to eliminate complicated cables and increase thedegree of freedom of the connection configuration, it has beenconsidered to connect the devices by a network (particularly, a wirelessnetwork) and transmit and receive audio signals and command messages inpackets.

Although audio cables are necessary for all the inputs and outputs,connection is completed by physically connecting them to the terminalsof the devices. On the contrary, wireless networks require setting ofSSIDs and passwords, for example, as shown in JP-A-2003-101546, and thesetting work is more complicated than the cable connection. Moreover,when it is necessary to change the destination of connection of a deviceto another destination of connection and perform reconnection, thisreconnection processing is complicated similarly to the initial setting.

SUMMARY OF THE INVENTION

Accordingly, an object of the present disclosure is to automate, in acommunication system where a plurality of communication devices areconnected by using a network, the procedure of connecting thecommunication devices to predetermined connection positions of thenetwork.

A communication system of the present disclosure is a communicationsystem including:

a control terminal device configured to be connected by a network; and

one or more communication devices,

wherein the one or more communication devices is connected to apredetermined connection position of the network;

wherein the control terminal device includes:

-   -   a communication portion configured to communicate with the one        or more communication devices through the network or by direct        connection; and    -   a storage portion configured to store a system management table        for managing the one or more communication devices of the        communication system;

wherein the control terminal device is configured to transmit a searchmessage to the entire network when the communication device isregistered into the communication system;

wherein the communication device includes a communication portionconfigured to communicate with the one or more control terminal devicesthrough the network or by direct connection;

wherein when the communication device is connected to the network, thecommunication device is configured to determine whether a connectionposition of the connected communication device on the network is thepredetermined connection position;

wherein when the communication device is connected to the predeterminedconnection position, the communication device is configured to respondto the search message through the network; and

wherein when the communication device is connected to the network but isnot connected to the predetermined connection position, thecommunication device is configured to cancel the connection with thenetwork, and after directly connecting to the control terminal deviceand obtaining information for connecting to the predetermined connectionposition of the network, the communication device is configured toconnect to the predetermined connection position of the network and torespond to the search message through the network.

A communication system of the present disclosure is a communicationsystem including:

a plurality of unit communication systems each having a control terminaldevice and one or more communication devices which are connected by anetwork,

wherein the control terminal device includes a communication portionconfigured to communicate with the one or more communication devicesthrough the network or by direct connection;

wherein the control terminal device is configured to transmit a networkconnection preparation command to the communication device in the unitcommunication system to which the control terminal device belongs when acommunication device is added to the unit communication system to whichthe control terminal device belongs;

wherein the communication device includes:

-   -   a communication portion configured to communicate with the        control terminal device through the network or by direct        connection; and    -   an operation portion configured to accept an operation of        connection to the communication system; and

wherein when the operation portion accepts the operation of connection,the communication device is configured to directly connect to thecontrol terminal device that transmits the network connectionpreparation command and to obtain information for connecting to thenetwork of the unit communication system in a case that thecommunication portion of the communication device is not connected tothe network or in a case that the network connection preparation commandis not received although the communication portion of the communicationdevice is connected to the network.

A communication device management method of the present disclosure is acommunication device management method of a communication systemincluding a control terminal device configured to be connected by anetwork and one or more communication devices and wherein the one ormore communication devices is connected to a predetermined connectionposition of the network,

wherein the control terminal device transmits a search message to theentire network;

wherein the communication device determines whether the communicationdevice itself is connected to the network;

wherein when the communication device is connected to the network, thecommunication device determines whether a network connection position ofthe communication device is the predetermined connection position;

wherein when the communication device is connected to the predeterminedconnection position, the communication device responds to the searchmessage through the network;

wherein when the communication device is not connected to thepredetermined connection position, the communication device cancels thenetwork connection, directly connects to the control terminal devicewithout through the network, and obtains information for connecting tothe predetermined connection portion of the network;

wherein the communication device having obtained the information forconnecting to the predetermined connection position of the networkconnects to the predetermined connection position of the network, andresponds to the search message through the network; and

wherein the control terminal device receives the response to the searchmessage, and registers the communication device into the communicationsystem.

A communication device of the present disclosure is a communicationdevice including:

a communication portion configured to communicate with a controlterminal device for managing the control terminal device through anetwork or by direct connection; and

a control portion,

wherein when the communication portion is connected to the network, thecontrol portion is configured to determine whether the connectionposition of the communication device on the network is the predeterminedconnection position;

wherein when the communication device is connected to the predeterminedconnection position, the communication portion is configured to respondto a search message through the network; and

wherein when the communication device is not connected to thepredetermined connection position although the communication portion isconnected to the network, the communication portion is configured tocancel the connection with the network, to obtain information forconnecting to the predetermined connection position of the network bydirectly connecting to the control terminal device, and then to respondto the search message through the network by connecting thepredetermined connection position of the network.

According to this disclosure, when a communication device registered ina first communication system is shifted to a second communicationsystem, the registration of the communication system can be shiftedafter the tree-form connection of the network is changed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram of an audio system to which thisdisclosure is applied.

FIG. 2 is a block diagram of a mobile phone to which this disclosure isapplied and that functions as a controller.

FIG. 3 is a block diagram of an audio device to which this disclosure isapplied.

FIG. 4 is a view showing an example of a system management table that isset in the host device and the controller.

FIG. 5 is a view showing an example of an audio control table that isset in the controller.

FIG. 6 is a view showing a procedure of communication between thecontroller and the audio device.

FIG. 7 is a view showing a procedure of communication between thecontroller and the audio device.

FIG. 8 is a view showing a procedure of communication between thecontroller and the audio device.

FIG. 9 is a view showing a procedure of communication between thecontroller and the audio device.

FIGS. 10A and 10B are flowcharts showing a system informationtransmission operation of the host device.

FIG. 11 is a view showing a communication procedure when the audiodevice is reconnected.

FIG. 12 is a view explaining a mode of changing the connectiondestination at the time of a system shift of the audio device.

FIG. 13 is a view explaining the mode of changing the connectiondestination at the time of the system shift of the audio device.

FIG. 14 is a flowchart showing the operation when a connect button of acontrol portion of the audio device is depressed.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

FIG. 1 is a view showing the configuration of an audio system to whichthe present disclosure is applied. This figure shows two audio systems10-1 and 10-2. The audio systems 10 each have a plurality of audiodevices 4 connected by a network 9 including a wired LAN 2 and an accesspoint (external access point) 3, and a multifunctional mobile phone 1(hereinafter, referred to as mobile phone 1) that functions as acontroller 1. The audio devices 4 transmit and receive audio signalswith each other through the network 9. The controller 1 transmitscommand messages to the audio devices 4 through the network 9.

The audio systems 10-1 and 10-2 are each identified by a unique systemID (hereinafter, sometimes abbreviated as LID). While the system ID maybe an arbitrary character string, in this embodiment, the system IDs ofthe audio systems 10-1 and 10-2 are 01 and 02, respectively. The systemID corresponds to the system identification information of the presentdisclosure.

The audio devices 4 (hereinafter, also referred to as component devices)constituting the audio systems 10 each have a wired LAN function and twowireless LAN functions. The audio devices 4 are capable of activating anaccess point by using one of the two wireless LAN functions. The accesspoint activated by the audio devices 4 is called an internal accesspoint 4A. To the internal access point 4A, a lower level audio device 4is connected. The internal access point 4A normally (other than at thetime of initial connection described later) operates in a stealth modeso that its existence is hardly known to other devices. The otherwireless LAN function functions as a child device of the wireless LAN,and is connected to the internal access point 4A of the higher levelaudio device 4 or an external access point 3.

The audio system 10-1 has a plurality of audio devices 4 (4-11 to 4-14)interconnected by the wired LAN 2 and the wireless LAN and themultifunctional mobile phone 1-1 that functions as the controller 1-1.The audio system 10-2 has a plurality of audio devices 4 (4-21 to 4-24)interconnected by the wired LAN 2 and the wireless LAN and themultifunctional mobile phone 1-2 that functions as the controller 1-2.These audio systems 10-1 and 10-2 share the wired LAN 2, and coexist inthe same segment.

To the wired LAN 2, the access point (external access point) 3 isconnected. The audio devices 4-11 and 4-21 are connected to the wiredLAN 2. The audio devices 4-12, 4-13, 4-22 and 4-23 are connected to theinternal access point 4A-11 and 4A-21 of the higher level audio devices4-11 and 4-21 by the wireless LAN. The audio device 4-14 is connected tothe external access point 3. Moreover, the controllers 1-1 and 1-2communicate with the audio devices 4 through the external access point37.

In this embodiment, the network 9 is formed of the wired LAN 2 and thewireless LAN including the external access point 3 and the internalaccess points 4A. As the wired LAN 2, for example, Ethernet (trademark:IEEE 802.3) is used, and as the wireless LAN, for example, Wi-Fi (IEEE802.11g) is used.

The audio devices 4 are called a root device, a node device, a leafdevice and a branch device according to the configuration of connectionto the wired LAN 2. The root device is the highest level deviceconnected to the wired LAN 2 directly (by cable), and in FIG. 1, theaudio devices 4-11 and 4-21 are root devices. The root devices are audiodevices registered first at the time of construction of the audiosystems 10-1 and 10-2, and serve as the base points of the audio systems10-1 and 10-2, respectively. The root device connects the lower levelaudio device 4 to the network and activates the internal access point 4Afor participation in the audio systems 10.

The node device is a middle level device connected to the root device(the internal access point 4A of the root device) by the wireless LAN,and in FIG. 1, the audio devices 4-12, 4-13, 4-22 and 4-23 are nodedevices. The node device connects the lower level audio device 4 to thenetwork and activates the internal access point 4A for participation inthe audio system 10.

The leaf device is a lower level device connected to the node device(the internal access point 4A of the node device) by the wireless LAN,and in FIG. 1, the audio device 4-24 is a leaf device. While the leafdevice does not activate the internal access point 4A, it may bestructured so as to activate it.

The branch device is an audio device 4 connected to the external accesspoints 3 and 7 by the wireless LAN separately from the above-describedtrees and communicates with other audio devices 4 in the audio systems10 through the wired LANs 2 and 6, and in FIG. 1, the audio device 4-14is a branch device. In each audio system 10, there is no limit to thenumber of branch devices. While the branch device does not activate theinternal access point 4A, it may be structure so as to activate it.

In this audio system, for transmission of high-quality audio signals, upto two node devices are allowed to be connected to a root device. Toeach node device, up to two leaf devices are allowed to be connected.The number of levels of the hierarchy of connection using the internalaccess point 4A is up to three of the root device, the node device andthe leaf device. Therefore, by the tree of the wireless LAN with a rootdevice at the top, up to seven audio devices including the root devicecan be connected. However, in the present disclosure, the number oflevels of the hierarchy of a tree and the number of lower level devicesthat can be connected to each audio device 4 are not limited to those ofthis embodiment.

The mobile phone 1 functions as the audio system controller(hereinafter, referred to as controller) 1 by an audio system controlprogram 70 (see FIG. 2) being activated. The mobile phone 1 (thecontroller 1) communicates with the audio devices 4 belonging to theaudio system 10 through the network 9. By this communication, thecontroller 1 controls the audio source reproduced in the audio system 10(for example, to which audio device 4 a piece of music of which audiodevice 4 is delivered) and the volume thereof. Moreover, the audiodevices 4 communicate with the audio devices 4 to which they belongthrough the network 9, and transmit and receive audio signals with eachother.

Next, referring to the block diagram of FIG. 2, the structure of themobile phone 1 will be described. The mobile phone 1 is amultifunctional telephone which is a so-called smartphone. The mobilephone 1 has a 3G/4G communication function which is a mobilecommunication network, a wireless LAN (Wi-Fi) communication function anda Bluetooth (trademark) communication function. The mobile phone 1functions as the controller 1 by activating the audio system controlprogram 70 which is an application program, communicates with the audiodevices 4 of the audio system through the external access point 3, andtransmits a command message responsive to an operation by the user tothe audio devices 4 to control the audio system.

The mobile phone 1 has, on a bus 26, a control portion 20, an operationportion 30, a media interface 31, a wireless LAN communication circuit32, a 3G/4G communication circuit 33 and a near field communicationcircuit 34 capable of performing Bluetooth (trademark) communication.The control portion 20 includes a CPU 21, a ROM (flash memory) 22, a RAM23, an image processor 24 and a sound processor 25. To the imageprocessor 24, a video RAM (VRAM) 40 is connected, and to the VRAM 40, adisplay portion 41 is connected. The display portion 41 includes aliquid crystal display. On the display, a standby screen, a telephonenumber and the like are displayed. Moreover, when the mobile phone 1functions as the controller 1, a screen for controlling the audiodevices 4 is displayed. To the sound processor 25, an amplifier 42including a D/A converter is connected, and to the amplifier 42, aspeaker 16 is connected.

The image processor 24 is provided with a GPU (graphics processing unit)that generates various images such as a standby screen, telephonenumbers and the like. When the audio system control program 70 isactivated, the image processor 24 generates an image of an audiocontroller according to the instruction of the CPU, and develops this onthe VRAM 40. The image developed on the VRAM 40 is displayed on thedisplay portion 41.

The sound processor 25 has a DSP (digital signal processor) thatencodes/decodes call voices. The sound processor 25 outputs thedecoded/generated voice to the amplifier 42. The amplifier 42 amplifiesthis voice signal and outputs it to the speaker 16.

The wireless LAN communication circuit 32 performs wirelesscommunication with a router according to a standard such as IEEE802.11g, and communicates with the audio devices 4 through the externalaccess points 3 and 7. The 3G/4G communication circuit 33 performs voicecalls and data communications through a mobile telephone communicationnetwork. The near field communication circuit 34 performs communicationwith other Bluetooth (trademark)-compatible devices, and performs, forexample, audio signal transmission and reception.

The operation portion 30 includes a touch panel formed on the displayportion 41, and detects touch operations and flick operations on thetouch panel. When the audio system control program 70 is activated, aplurality of operation elements such as a setup button and a scan buttonare displayed on the display portion 41. The operation portion 30detects a touch operation by the user on the touch panel and itscoordinates, and determines which operation element has been operated.

To the media interface 31, a memory card 15 is connected. The memorycard 15 is, for example, a micro SD card. The audio system controlprogram 70 is stored in the memory card 15 or the ROM 22. In thisembodiment, as shown in FIG. 2, the audio system control program 70 isstored in the memory card 15. The audio system control program 70 may bedownloaded by 3G/4G or wireless LAN data communication or may beprestored in the ROM 22 or the memory card 15. Moreover, a storage area71 storing the configuration of the audio system is set in the memorycard 15.

The ROM 22 stores a basic program for executing calls and applicationprograms of this mobile phone 1. Moreover, the ROM 22 is a flash memory,and is capable of storing downloaded application programs in addition tothe basic program. In the RAM 23, a work area used when the CPU 20executes the audio system control program 70 is set.

Next, referring to FIG. 3, the structure of the audio device 4 will bedescribed. The audio device 4 has a control portion 50, an audioprocessing portion 51 and an operation portion 59, and has two wirelessLAN communication portions (RF modules) 56 and 57 and a wired LANcommunication portion 58. The operation portion 59 has a connect button59A. The control portion 50 includes a CPU and a memory, and stores anaudio system program. The control portion 50 controls the operations ofthe audio processing portion 51, the wireless LAN communication portions56 and 57 and the wired LAN communication portion 58 by the audio systemprogram. Moreover, when the connect button 59A is depressed, the controlportion 50 executes an initial connection operation which is anoperation for connecting this audio device 4 to the network 9. Detailsof the initial connection operation will be described later.

The wireless LAN communication portion 56 performs wirelesscommunication with the external access point 3 or the internal accesspoint 4A according to a wireless LAN standard such as IEEE 802.11g.Moreover, the other wireless LAN communication portion 57 is activatedas an access point (the internal access point 4A), and relays otheraudio devices (for example, the audio devices 4-2 and 4-3) to the wiredLAN 2. Moreover, the wireless LAN communication portion 57 is alsoactivated as a temporary access point for initial connection at the timeof initial connection of this audio device 4, and communicates with thecontroller 1 (the mobile phone 1). The operation at the time of theinitial connection will be described later. The two wireless LANcommunication portions 56 and 57 may be implemented by one piece ofhardware operating in a time-sharing manner. The wired LAN communicationportion 58 has a cable connector, and performs communication through thewired LAN 2 and the external access point 3 according to a communicationstandard such as IEEE 802.3. To the access point 3, the controller(mobile phone) 1 is connected, and the control portion 50 communicateswith the controller 1 through the network 9 to transmit the operatingstatus and receive command messages.

The SSID and password of the internal access point 4A are characterstrings that can be deduced from the MAC address of the wireless LANcommunication portion 57. For example, a MAC address which is expressedin octets is made the SSID and the lower three octets (the device ID+theserial number) are made the password. Thereby, the audio device thatnewly participates in the audio system can detect the internal accesspoint 4A based on the SSID, that is, based on the vendor ID of the MACaddress and the device ID, and can generate a password by itself andconnect to the internal access point 4A. Thereby, the input of the SSIDand the password by the user when connection is made to the internalaccess point 4A can be omitted. The method of generating the SSID andpassword of the internal access point 4A is not limited to theabove-described one.

The audio processing portion 51 has a tuner 52, an audio circuit 53 anda power amplifier 54. The tuner 52 receives an audio signal from an FMbroadcast or the Internet and inputs it to the audio circuit 53. Theaudio circuit 53 performs processing such as equalization and volumecontrol on the inputted audio signal, and then, outputs this processedaudio signal to the power amplifier 54. The power amplifier 54 amplifiesthe inputted audio signal and outputs it to an externally connectedspeaker 55. The speaker 55 emits the inputted audio signal as a sound.

While the audio devices 4-1 to 4-8 may be devices different from oneanother, the basic structure of the communication function and the audiosignal processing function is that shown in FIG. 3.

FIG. 4 and FIG. 5 are views showing examples of tables that manage theaudio system. FIG. 4 is a system management table that manages theconnection configuration of the audio devices 4 in the network 9. FIG. 5is an audio control table that manages the operation of the audiodevices 4 in the audio system 10. The system management table is usedfor the management of network connection mainly by the root devices 4-11and 4-21. The audio control table is used for the control of audiosource reproduction mainly by the controllers 1-1 and 1-2. The tablesshown in FIG. 4 and FIG. 5 are examples and do not show the structure ofany of the audio system 10-1 or 10-2.

The system management table stores the connection configuration of theaudio devices 4 (component devices) constituting the audio system 10-n(n=1, 2), and is created by the controller 1 when the audio system 10 isconstructed. Moreover, when a new audio device 4 is added to the audiosystem 10, the controller 1 performs updating to add this audio device4. The created or added and updated system management table istransmitted from the controller 1 to the root devices 4-n1. Thereafter,the system management table is updated by the root device 4-n1 everytime disconnection or reconnection of any of the component devicesoccurs while the audio system 10 is operating. Moreover, the root device4-n1 periodically transmits all or some of the contents of the systemmanagement table as system information to the component devices and thecontroller 1. Thereby, the component devices and the controller 1 canalways hold the latest system information.

The system management table is identified by the system ID foridentifying this audio system 10. The component devices each store, in astate of being associated with the device ID of the device, informationsuch as the higher side (child device side)/lower side (internal accesspoint side) MAC address, the higher side/lower side IP address, thestage of connection from the root device 4-n1 (hop count), the presenceor absence of activation of the internal access point, the number oflower devices connected to the internal access point 4A (the number ofchildren) and the operating status (communication possible/impossible)information (active). When any of the component devices is disconnectedfrom the root device 4-1 (when communication ceases), the column of thedevice is made inactive, and when the device is reconnected, updating isperformed with the contents of the reconnection to make the columnactive again.

While the audio devices 4 connected to the network 9 each have anindividual IP address, for each of the audio systems 10-1 and 10-2, amulticast address is set as a multicast group. By transmitting an IPpacket to the multicast address, all the components of the audio system10-1 or the audio system 10-2 can be made to receive this packet.

The audio control table of FIG. 5 stores, in a state of being associatedwith the device ID of each device, the higher side IP address, thedevice kind, the installation place and the operating status informationof each component device and various setting information such as thevolume value. The columns of the audio control table and the columns ofthe system management table are associated by the device IDs,respectively. The controller 1 creates a control screen based on thecontents of the audio control table, and accepts the control of eachcomponent device by the user.

When the audio system 10-n is constructed, the root device 4-n1 is setfirst to construct the audio system 10-n. Thereafter, audio devices 4-nmother than the root device 4-n1 are added to this audio system 10-n. Inthis case, the user performs work by the following procedure: The audiodevice 4-n1 serving as the root device is connected to a cable to thewired LAN 2. On the mobile phone 1, the controller 1-n is activated in asetup mode. The connect button 59A of the audio device 4 n-1 isdepressed. When the user performs the above-described work, thecontroller 1-n and the root device 4-n1 communicate with each other, andautomatically construct the audio system 10-n. Thereafter, when a newaudio device 4-nm is added to the audio system 10-n, the user activatesthe controller 1-n in the setup mode, turns on the audio device 4-nm tobe added (activates the wireless LAN communication portions 56 and 57)and depresses the connect button 59A; then, the audio device 4-nmcommunicates with the controller 1-n and the root device 4-n1 and isautomatically added to the audio system 10-n.

Referring to FIG. 6 to FIG. 9, the procedure of the communicationbetween the controller 1 and the audio device 4 when the audio system 10is constructed and when the audio device 4 is added to the audio system10 will be described. In this description, the designation “−n, n”indicative of the number (location ID) of the audio system is omitted.

FIG. 6 is a view showing the procedure of communication between thecontroller 1 and the audio device 4-1 serving as the root device whenthe audio system 10 is newly constructed. The mobile phone 1 functionsas the controller 1 as the audio system control program 70 is activated.When the controller 1 is set to the setup mode by an operation by theuser (S31), a guidance screen to prompt for depression of the connectbutton 59A of the audio device 4 is displayed on the display portion 41.According to this guidance on the screen, the user depresses the connectbutton 59A of the audio device 4-1 (S41). Then, the controller 1searches for a new audio device connected to the wired LAN 2 (S32). Thissearch is performed by transmitting a message requiring a reply such aspolling. The audio device 4-1 responds to this search (S42). Thereby,the controller 1 and the audio device 4-1 start intercommunicationthrough the wired LAN 2 and the access point 3.

The audio device 4-1 transmits its own device information to thecontroller 1 (S43). The controller 1 constructs a new audio system 10with this audio device 4-1 as the root device. A system ID is assignedto the audio system 10 (S34), the system management table and the audiocontrol table shown in FIG. 4 and FIG. 5 are created, and the audiosystem 10 with the currently communicating audio device 4 as the rootdevice is constructed (S35). When the audio system 10 is constructed,the system management table is transmitted to the audio device 4-1 thatis made the root device (S36), and the setup mode is ended (S37). Theaudio device 4-1 receives this system management table (S44), and storesit (S45). Thereby, the audio system 10 is constructed in which the audiodevice 4-1 is the root device which is the core component. Thereafter,the reproduced music, the volume thereof and the like are controlled bythe controller 1. The audio device 4 activates the access point in thestealth mode (S46).

FIG. 7 is a view showing the procedure of communication when a new audiodevice is added to the audio system 10 having been constructed. Thecomponent device is the audio device 4 having already been a componentof the audio system 10, and in this example, the root device or the nodedevice where the internal access point 4A is activated. The new deviceis an audio device 4 to be newly added from now.

When the mobile phone 1 functioning as the controller 1 is set to thesetup mode by an operation by the user (S51), the controller 1 transmitsan initial join command to the component device which is the audiodevice 4 already registered in this audio system 10 (S52), and providesan instruction to cancel the stealth mode of the internal access point4A. Thereby, the component device cancels the stealth mode of theinternal access point 4A and transmits a beacon frame to notify its ownpresence to enable a passive scan of the new device (S61). Next, thecontroller 1 starts search for the new device (S53). This search isperformed by broadcasting a new device search message to the entirenetwork 9 beyond the bounds of the audio system 10.

Moreover, when the controller 1 is set to the setup mode, a guidancescreen to prompt for depression of the connect button 59A of the audiodevice 4 (new device) is displayed on the display portion 41, and theuser depresses the connect button 59A of the new device according to theguidance of this screen (S71). When the connect button 59A is depressedby the user (S71), an initial connection mode is set, and a connectableaccess point is searched for (passive scan) (S72). By this search, thenew device detects the internal access points 4A of the componentdevices as connectable access points. As described above, the internalaccess point 4A has an SSID by which it can be identified that it is adevice of the audio system 10 when viewed from the new device, andconnection can be made by generating a password from the SSID (or theMAC address). The new device selects the nearest (theeasiest-to-connect) one from among the detected internal access points4A, and temporarily connects to the selected internal access point 4A byusing this SSID and the generated password (S73). This connection is atemporary connection for obtaining system information and is not aregular connection for participating in the audio system 10. Then, thecurrent system information of the audio system 10 is obtained from theconnected internal access point 4A (component device) (S62, S74). Thesystem information is information formed of all or some of the contentsof the system management table, and is periodically updated by the rootdevice 4-1 and delivered to other component devices. Based on theobtained system information, the new device selects an optimum accesspoint in order to participate in the audio system 10 (S75). Thisselection is made based on the field intensity of each access point, thenumber of stages of connection from the root device 4-1, the number ofcomponent devices connected to the access point and the like, and anaccess point that is highly likely excellent in communication conditionsis selected.

The example of FIG. 7 (example in which S100 is not executed) shows theflow in a case where determining that the temporarily connected internalaccess point 4A is optimum also in the regular connection, thedestination of connection is not changed. For example, a case whereconnection is made to the internal access point 4A-1 of the root device4-1 corresponds to this. When the destination of connection is changedfrom the temporarily connected internal access point 4A at the regularconnection, the procedure of FIG. 8 or FIG. 9 is executed in the sectionof S100 shown in FIG. 7. When the regular connection is completed (inthe case of FIG. 7, after temporary connection is made regularconnection), the new device responds to the new device search message(S53) from the controller 1 (S76). This enables the new device tocommunicate with the controller 1. Thereby, the new device has itsreproduced music, the volume thereof and the like controlled by thecontroller 1, and becomes a component of the audio system 10.

The new device transmits its own device information to the controller 1(S77). The controller 1 receives this device information (S54),registers this new audio device 4 into the system management table andthe audio control table to update them (S55). The controller 1 transmitsthe updated system management table to the root device 4-1 (S56). Theroot device 4-1 periodically delivers system information formed of allor some of the contents of the system management table to the othercomponent devices as a connection confirmation message described withreference to FIG. 10. The system management table is transmitted to allthe audio devices 4 of the audio system 10 (S56), and the setup mode isended (S57). The notification of the end of the setup mode istransmitted to all the audio devices 4. The notification of the end ofthe setup mode may be provided to the root device 4-1 by the controller1 so that the root device 4-1 transfers it to the other audio devices 4of the audio system 10.

The new device having received the system information from the rootdevice 4-1 stores this system information (S78). Thereafter, the newdevice activates the internal access point 4A in the stealth mode (S79).Moreover, the component device having received the system informationfrom the root device 4-1 updates the internally stored systeminformation with this information (S63). Then, the internal access point4A is returned to the stealth mode (S64). By the above-describedprocessing, a new device can be added to the audio system 10 having beenconstructed. In both the component devices and the new device, it isonly in the root device and the node device that the internal accesspoint 4A is activated in the stealth mode, and the processing of S64 andS79 is not performed in the leaf device and the branch device.

FIG. 8 is a view showing the communication procedure when the new devicedisconnects from the temporarily connected internal access point 4A atS75 and reconnects to another internal access point 4A in the tree. Whenanother internal access point 4A is selected as the destination of theregular connection at S75 of FIG. 7, the new device disconnects from thecurrently temporarily connected internal access point 4A (S81), andregularly connects to the selected internal access point 4A (S82).Thereafter, the process proceeds to S76 of FIG. 7.

FIG. 9 is a view showing the communication procedure when the new devicedisconnects from the temporarily connected internal access point 4A atS75 and reconnects to the external access point 3 as the branch device.When the external access point 3 is selected as the destination of theregular connection at S75 of FIG. 7, the new device disconnects thecurrently temporarily connected internal access point 4A (S91), andactivates on a stand-alone basis the temporary access point for only atthe time of initial connection (S92). That is, the internal access point4A that is not connected to the wired LAN 2 and is connected only to thenew device is activated. The controller 1 previously stores the SSID andpassword of the temporary access point of this initial connection. Thatis, the SSID and the password are previously written as data in theaudio system control program 70. Therefore, the controller 1 detectsthis temporary access point in the new device search started at S53,temporarily disconnects from the external access point 3, and connectsto the temporary access point activated by the new device (S83). It ishighly possible that the controller 1 cannot obtain the SSID andpassword of the external access point 3 from the system program of themobile phone 1, in this example, the user is required to input the SSIDand password of the external access point 3 (S84). The input of the SSIDis performed by a method in which a list of connection destinations(SSID) that are seen at that time is displayed on a display and the useris made to select the SSID of the external access point 3. The password(normally shown on the main body of the external access point 3) is madeto be input by the user.

Then, this inputted connection information is transmitted to the newdevice activating the temporary access point (S85). The new devicereceives this connection information (S93). After transmitting theconnection information (the SSID, the password) of the external accesspoint 3 to the new device, the controller 1 disconnects from thetemporary access point (S86). When receiving the connection informationof the external access point 3 from the controller 1, the new devicestops the temporary access point (S94). The controller 1 reconnects tothe temporarily disconnected external access point 3 (S87). The newdevice also connects to the external access point 3 by using theobtained connection information (S95). Returning to the procedure ofFIG. 7 thereafter, the controller 1 performs new device search (S53),and the new device responds thereto (S76). When the connectioninformation of the external access point 3 is contained in the systeminformation obtained from the temporarily connected component, theprocessing shown at S101 (S83 to S87, S92 to 94) is omitted andreconnection to the external access point is made as in FIG. 8.

By the procedures of FIG. 6 to FIG. 9 being separately performed at theaudio systems 10-1 and 10-2, the two audio systems 10-1 and 10-2 asshown in FIG. 1 are constructed.

As described above, the root device 4-n1 transmits the systeminformation periodically (once every two seconds) to the other audiodevices (component devices) 4-nm of the audio system 10-n. The systeminformation is formed of the (internal access point side) MAC address,the IP address, the number of stages of connection from the root device4-1 (hop count), the presence or absence of activation of the internalaccess point and the number of lower level devices connecting to theinternal access point 4A of each component device, and the connectioninformation of the external access point 3. The root device 4-n1transmits this system information as an echo request packet (ping) toeach component device 4-nm. Hereinafter, this packet will be referred toas system information packet.

Referring to FIG. 10, the periodically executed system informationpacket transmission processing will be described. In this description,the designation “−n, n” indicative of the number (location ID) of theaudio system is omitted.

In FIG. 10A, the root device 4-1 creates the system information packetbased on its own system management table (S111). The system informationpacket has a structure of an IP packet containing a UDP datagram withthe system information shown in FIG. 10B as the data body, and themulticast address that is set for this audio system 10 is written as thedestination address of the IP header. The root device 4-1 transmits thesystem information packet to the multicast address assigned to the audiosystem 10. Therefore, although the system information packet isdelivered to all the component devices 4 of this audio system 10 (forexample, 10-1), it is not delivered to the component devices 4 of theother audio systems 10 (for example, 10-2) (discarded).

When receiving the system information packet, the component devices 4each update the system information owned by itself with the systeminformation contained in this packet, and returns to the root device 4-1an acknowledgement packet (ACK) to the effect that the systeminformation packet has been received. The root device 4-1 receives theacknowledgement packet from the component device (S113), and determineswhether a reply has been returned from all the component devices (S114).When a reply has been returned from all the component devices (YES atS114), the process ends without doing anything. When there is acomponent device from which no reply has been returned (NO at S114), thecomponent device is rewritten to be non-active to update the systemmanagement table (S115). The creation of the next system informationpacket is performed with the contents of this updated system managementtable. For this reason, the component devices are capable of alwaysobtaining the latest system information. The contents of the updatedmanagement table are also notified to the controller 1. While the systeminformation is transmitted by multicast in the description of FIG. 10,it may be individually transmitted to each component device by unicast.

Scenes where the component device cannot return the ACK to the rootdevice 4-1 include a case where the own device is responsible such aswhen the own device is powered off (unplugged) and a case where a higherlevel device is responsible such as when the higher level device of thetree is powered off (unplugged) or when the radio wave condition of thecommunication is poor. When communication with the higher levelcomponent device (the internal access point 4A) is disconnected from thehigher level component device, component devices (particularly, the nodedevice and the leaf device) search for another connectable access pointand automatically try reconnection. The disconnection of communicationwith the higher level internal access point 4A can be determined, forexample, by that the above-described system information packet is nottransmitted, that the notification of update of an encryption key is nottransmitted or that there is no reply to a keep-alive packet.

Now, a case will be described where an audio device 4 (for example,4-13) registered in an audio system 10 (for example, 10-1) is shifted toanother audio system 10 (for example, 10-2).

As described with reference to FIG. 7, when receiving the new devicesearch message in a state of being connected to the network 9 (S75 andsucceeding steps), the audio device 4 responds thereto (S76), and theprocess is proceeded with so that the audio device 4 belongs to theaudio system where the message is transmitted (S54, S78 and succeedingsteps). When the procedure of FIG. 7 is executed in a case where anaudio device 4 already registered in an audio system 10 is shifted toanother audio system 10, the audio device 4 comes to belong to anotheraudio system 10 while being connected to the former tree.

As an example, when the audio device 4-13 shown in FIG. 1 is shiftedfrom the audio system 10-1 to the audio system 10-2, the controller 1-2is set to the setup mode by the user, and the connect button 59A of theaudio device 4-13 is depressed. When the procedure of FIG. 7 is executedin this case, since the audio device 4-13 has already been connected tothe network 9 through the audio device 4-11 which is the root device ofthe audio system 10-1, it can respond under the status quo to the newdevice search message broadcast from the controller 1-2, so that thesystem to which the audio device 4-13 belongs is changed to the audiosystem 10-2 while being connected to the tree (the root device 4-11) ofthe audio system 10-1. When the connection configuration becomes likethis, efficient audio signal transmission in each audio system 10(particularly, the audio system 10-1) can be obstructed.

Therefore, even in a case where the audio device 4 where the connectbutton 59A is depressed is already connected to the network 9 throughthe internal access point 4A, when the audio device 4 does not receivethe initial join command, that is, when it cannot confirm that thecontroller 1 of the audio system 10 to which it belongs is in the setupmode, it does not respond to the new device search message transmittedby broadcast, and after performing reconnection to the network, respondsto this message. Thereby, when the audio system 10 to which the audiodevice 4 belongs is changed, the network connection configuration issimultaneously changed to an appropriate one. Hereinafter, the procedurewill be described.

FIG. 11 is a view showing the communication procedure when an audiodevice 4 (for example, 4-13) registered in an audio system 10 (forexample, 10-1)) is shifted to another audio system 10 (for example,10-2). In this example, description will be given by using as an examplea case where the audio device 4-13 is shifted from the audio system 10-1to the audio system 10-2. FIG. 12 and FIG. 13 are views showing a changeof the connection configuration when the audio system to which the audiodevice 4-13 belongs is shifted from the audio system 10-1 to the audiosystem 10-2.

In FIG. 11, in order to add the audio device 4-13 to the audio system10-2, the controller 1-2 is set to the setup mode by an operation by theuser (S111). Then, the controller 1-2 transmits the initial join commandto the audio devices (component devices) 4-21 to 24 already registeredin the audio system 10-2 (S112) to provide an instruction to cancel thestealth mode of the internal access point 4A (S121). Then, thecontroller 1-2 starts search for the new device (S113). This search isperformed by broadcasting a new device search message to the entirenetwork 9 beyond the bounds of the audio system 10-2.

Moreover, when the controller 1-2 is set to the setup mode, a guidancescreen to prompt for depression of the connect button 59A of the audiodevice 4 to be added is displayed on the display portion 41 as describedabove, and the user depresses the connect button 59A of the audio device4-13 according to the guidance of this screen (S131). When the connectbutton 59A is depressed by the user (S131), the audio device 4-13 is setto the initial connection mode, and determines the condition of its ownconnection to the network 9 (S132). When the audio device 4-13 is notconnected to the network 9, the process proceeds to the procedure of S72and succeeding steps of FIG. 7. When the audio device 4-13 is connectedto the external access point 3 wirelessly or when it is connected to thenetwork 9 by cable, determining that the connection is valid, theprocess proceeds to S76 and succeeding steps of FIG. 7. When the audiodevice 4-13 is connected to the internal access point 4A of anotheraudio device 4 and receives the initial join command, determining asreconnection in the audio system 10 to which it currently belongs, theprocess proceeds to the procedure of S72 and succeeding steps of FIG. 7(assuming that the result of the determination at S132 in any of theabove is the rightward arrow, the description of the following procedureis omitted). On the other hand, when the audio device 4-13 is connectedto the internal access point 4A of another audio device 4 but does notreceive the initial join command, that is, when the connect button 59Aof the audio device 4-13 is depressed as shown in FIG. 12, since theinitial join command issued by the controller 1-2 is delivered to theaudio system 10-2 and is not transmitted to the audio device 4-13, theaudio device 4-13 does not belong to the audio system 10-2, anddetermining as a shift to the tree of the audio system 10-2, theprocedure of FIG. 11 is executed.

The audio device 4-13 disconnects from the currently connected internalaccess point 4A (S133), and activates on a stand-alone basis a temporaryaccess point for only at the time of initial connection (S134). Thecontroller 1-2 previously stores the SSID and password of the temporaryaccess point of this initial connection. That is, these SSID andpassword are previously written as data in the audio system controlprogram 70. Therefore, the controller 1-2 detects this temporary accesspoint in the new device search started at S113, temporarily cancels theconnection with the external access point 3, and connects to thetemporary access point activated by the new device (S114).

Then, the controller 1-2 transmits the system information of the audiosystem 10-2 to the audio device 4-13 (S115), and the audio device 4-13receives the system information (S135). After transmitting the systeminformation to the audio device 4-13, the controller 1-2 cancels theconnection with the temporary access point (S116). In parallel, theaudio device 4-13 stops the temporary access point (S136). Thecontroller 1-2 again connects to the external access point 3 theconnection with which is temporarily canceled (S117). The audio device4-13, the new device, selects an optimum access point in order to shiftto the audio system 10-2 based on the obtained system information(S137). This selection is made based on the field intensity of eachaccess point, the number of stages of connection from the root device4-1, the number of component devices connected to the access point andthe like, and an access point that is highly likely excellent incommunication conditions is selected from among access points includingthe external access point 3 and the internal access point 4A. The audiodevice 4-13 connects to the selected access point (S138). At this time,the audio device 4-13 is connected to the internal access point 4A-22 ofthe audio device 4-22, for example, as shown in FIG. 13. Thereafter, theaudio device 4-13 responds (S76) to the new device search message (S113,S53) of the controller 1-2 over the path over which it is connected, andthe process shifts to the procedure of FIG. 7.

By the above-described procedure, after connection is changed from thetree of the audio system 10-1 to the tree of the audio system 10-2, theaudio device 4-13 responds to the controller 1-2, and registration inthe audio system 10-2 is performed. In the audio system 10-1, the tablesof FIGS. 4 and 5 are updated by the ceasing of the response from theaudio device 4-13 at S114 of FIG. 10.

In the above, regarding when the connect button 59A of the audio device4 is depressed, the following cases are described with reference to FIG.6, FIG. 7 and FIG. 11: a case where the audio system 10 is newlyconstructed (a case where the audio device 4 is made the root device); acase where the audio device 4 is added to the audio system 10; and acase where the audio system 10 to which the audio device 4 belongs ischanged. While the operation of the audio device 4 is described on theassumption that the operation after the depression of the connect button59A is determined in FIG. 6, FIG. 7 and FIG. 11, in actuality, the audiodevice 4 switches the operation (to FIG. 6, FIG. 7 or FIG. 11) accordingto the condition of connection to the network 9 since it is unknown whatthe registration destination audio system 10 is like when the connectbutton 59A is depressed. The operation of the audio device 4 when theconnect button 59A is depressed will be described with reference to FIG.14.

In FIG. 14, when the connect button 59A is depressed (S150), the controlportion 50 of the audio device 4 determines whether the own device isconnected to the network 9 (S151). When it is connected to the network 9(YES at S151), the configuration of connection to the network 9 isdetermined (S152). When it is connected to the network 9 (the wired LAN2) through the external access point 3, the process proceeds to S72 ofFIG. 7. When it is directly connected to the wired LAN 2 (by cable), theprocess proceeds to S42 of FIG. 6 (when the audio system 10 isconstructed) or S76 of FIG. 7 (when the device is added to the audiosystem 10).

When the own device is connected to the network 9 through the internalaccess point 4A, that is, when it is connected to the tree of the audiosystem 10, the control portion 50 determines whether the initial joincommand is received from the controller 1 of the audio system 10 or not(S153). When the initial join command is received (YES at S153), it isdetermined that reconnection in the same audio system 10 is to beperformed, and the process proceeds to S72 of FIG. 7 (AP search). On theother hand, when the initial join command is not received (NO at S153),it is determined that the processing of shifting from the audio system10 to which it currently belongs to another audio system 10 is to beperformed, the currently connected internal access point 4A isdisconnected (S133), a temporary access point is activated by thewireless LAN communication portion 57 (S134), and the process proceedsto S135 of FIG. 11 (activate temporary AP). Moreover, when it isdetermined that the audio device 4 is not connected to the network 9 atS151 (No at S151), the temporary access point is activated by thewireless LAN communication portion 57 in order to communicate with thecontroller 1 that is set in the setup mode (S134), and the processproceeds to S135.

The audio devices of this disclosure may be audio/video (AV) deviceshaving a video reproduction function, and include a system where thesecoexist. Moreover, while in this embodiment, the control terminal deviceis implemented as the mobile phone 1 where the audio system controlprogram 70 (application program) is installed, a different structure maybe adopted. For example, it may be a tablet terminal where the audiosystem control program 70 is installed, or may be a dedicated terminaldevice.

Now, the embodiment of the present disclosure is summarized as follows:

(1) A communication system of the present disclosure is a communicationsystem including: a control terminal device configured to be connectedby a network; and one or more communication devices, wherein the one ormore communication devices is connected to a predetermined connectionposition of the network; wherein the control terminal device includes: acommunication portion configured to communicate with the one or morecommunication devices through the network or by direct connection; and astorage portion configured to store a system management table formanaging the one or more communication devices of the communicationsystem; wherein the control terminal device configured to transmit asearch message to the entire network when the communication device isregistered into the communication system; wherein the communicationdevice includes a communication portion configured to communicate withthe one or more control terminal devices through the network or bydirect connection; wherein when the communication device is connected tothe network, the communication device is configured to determine whethera connection position of the connected communication device on thenetwork is the predetermined connection position; wherein when thecommunication device is connected to the predetermined connectionposition, the communication device configured to respond to the searchmessage through the network; and wherein when the communication deviceis connected to the network but is not connected to the predeterminedconnection position, the communication device is configured to cancelthe connection with the network, and after directly connecting to thecontrol terminal device and obtaining information for connecting to thepredetermined connection position of the network, the communicationdevice is configured to connect to the predetermined connection positionof the network and to respond to the search message through the network.

(2) In the communication system according to the above (1), for example,when receiving a response to the search message from the communicationdevice, the control terminal device is configured to register thecommunication device into the system management table.

(3) In the communication system according to the above (1) or (2), forexample, the communication device includes an operation portion isconfigured to accept an operation of registration into the communicationsystem, and to check whether or not the communication portion of thecommunication device is connected to the network when the operationportion of the communication device accepts the operation ofregistration.

(4) In the communication system of the present disclosure, in thecommunication system according to the above (3), for example, when thecommunication portion of the communication device is not connected tothe network, after the communication device directly connects to thecontrol terminal device and obtains information for the communicationdevice to connect to the predetermined connection position of thenetwork, the communication device is configured to connect to thepredetermined connection position of the network and to respond to thesearch message through the network.

(5) In the communication system according to any of the above (1) to(4), for example, the control terminal device is configured to transmita network connection preparation command to the one or morecommunication devices in the communication system while transmitting thesearch message to the entire network; and the communication device isconfigured to determine whether the communication device itself isconnected to the predetermined connection position of the network or notbased on whether the network connection preparation command is receivedor not.

(6) In the communication system according to any of the above (1) to(5), for example, the communication device includes a first wirelesscommunication portion configured to function as a wireless relay deviceand a second wireless communication portion configured to function as achild device connected to another device; and the communication deviceis configured to be connected to the predetermined connection positionof the network by the second wireless communication portion of thecommunication device being connected to the first communication portionof a higher level communication device.

(7) In the communication system according to any of the above (1) to(6), for example, the predetermined connection position of the networkis a predetermined communication device in a connection configurationwhere the more than one communication device is connected as a node or aroot on the network.

(8) A communication system in which a first system and a second systemwhich are unit communication systems each having the structure accordingto any one of the above (1) to (6) are formed on the same network is acommunication system, wherein when the control terminal device of thesecond system transmits the search message and the communication deviceof the first system accepts the operation of registration, thecommunication device of the first system is configured to cancel thenetwork connection of the predetermined connection position of the firstsystem, to directly connect to the control terminal device of the secondsystem, to obtain information for connecting to the predeterminedconnection position of the second system, and to connect to thepredetermined connection position of the second system.

(9) A communication system of the present disclosure is a communicationsystem including: a plurality of unit communication systems each havinga control terminal device and one or more communication devices whichare connected by a network, wherein the control terminal device includesa communication portion configured to communicate with the one or morecommunication devices through the network or by direct connection;wherein the control terminal device is configured to transmit a networkconnection preparation command to the communication device in the unitcommunication system to which the control terminal device belongs when acommunication device is added to the unit communication system to whichthe control terminal device belongs; wherein the communication deviceincludes: a communication portion configured to communicate with thecontrol terminal device through the network or by direct connection; andan operation portion configured to accept an operation of connection tothe communication system; and wherein when the operation portion acceptsthe operation of connection, the communication device is configured todirectly connect to the control terminal device that transmits thenetwork connection preparation command and to obtain information forconnecting to the network of the unit communication system in a casethat the communication portion of the communication device is notconnected to the network or in a case that the network connectionpreparation command is not received although the communication portionof the communication device is connected to the network.

(10) In the communication system according to any of the above (1) to(9), for example, the communication device is an audio device.

(11) A communication device management method of the present disclosureis a communication device management method of a communication systemincluding: a control terminal device configured to be connected by anetwork and one or more communication devices and wherein the one ormore communication devices is connected to a predetermined connectionposition of the network, wherein the control terminal device transmits asearch message to the entire network; wherein the communication devicedetermines whether the communication device itself is connected to thenetwork; wherein when the communication device is connected to thenetwork, the communication device determines whether a networkconnection position of the communication device is the predeterminedconnection position; wherein when the communication device is connectedto the predetermined connection position, the communication deviceresponds to the search message through the network; wherein when thecommunication device is not connected to the predetermined connectionposition, the communication device cancels the network connection,directly connects to the control terminal device without through thenetwork, and obtains information for connecting to the predeterminedconnection portion of the network; wherein the communication devicehaving obtained the information for connecting to the predeterminedconnection position of the network connects to the predeterminedconnection position of the network, and responds to the search messagethrough the network; and wherein the control terminal device receivesthe response to the search message, and registers the communicationdevice into the communication system.

(12) In the communication device management method according to theabove (11), for example, when the communication device is not connectedto the network, the communication device directly connects to thecontrol terminal device without through the network, and obtainsinformation for connecting to the predetermined connection position ofthe network from the control terminal device.

(13) In the communication device management method according to theabove (11) or (12), for example, the control terminal device transmits anetwork connection preparation command to the one or more communicationdevices in the communication system while transmitting the searchmessage to the entire network; and the communication device determineswhether the communication device itself is connected to thepredetermined connection position of the network or not based on whetherthe network connection preparation command is received or not.

(14) In the communication device management method according to any ofthe above (11) to (13), for example, the communication device is anaudio device.

(15) A communication device of the present disclosure is a communicationdevice including: a communication portion configured to communicate witha control terminal device for managing the control terminal devicethrough a network or by direct connection; and a control portion,wherein when the communication portion is connected to the network, thecontrol portion is configured to determine whether the connectionposition of the communication device on the network is the predeterminedconnection position; wherein when the communication device is connectedto the predetermined connection position, the communication portion isconfigured to respond to a search message through the network; andwherein when the communication device is not connected to thepredetermined connection position although the communication portion isconnected to the network, the communication portion is configured tocancel the connection with the network, to obtain information forconnecting to the predetermined connection position of the network bydirectly connecting to the control terminal device, and then to respondto the search message through the network by connecting thepredetermined connection position of the network.

(16) In the communication device according to the above (15), forexample, when the communication portion is not connected to the network,after connection is directly made to the control terminal device and theinformation for connecting to the predetermined connection position ofthe network is obtained, connection is made to the predeterminedconnection position of the network and a response to the search messageis made through the network.

(17) In the communication device according to the above (15) or (16),for example, the control portion is configured to determine whether thecommunication device itself is connected to the predetermined connectionposition of the network or not based on whether a network connectionpreparation command transmitted from the control terminal device isreceived or not.

(18) In the communication device according to any of the above (15) to(17), for example, the communication portion includes a first wirelesscommunication portion that functions as a wireless relay device and asecond wireless communication portion that functions as a child deviceconnected to another device; and connection of the communication deviceis made to the predetermined connection position of the network by thesecond wireless communication portion thereof being connected to a firstcommunication portion of another communication device of a higher level.

(19) In the communication device according to any of the above (15) to(18), for example, the communication device the communication devicefurther includes an audio signal processing portion configured toprocess an audio signal.

According to the present disclosure, when an audio device registered ina first audio system is shifted to a second audio system, for example,it is possible to change the tree-form connection configuration of thenetwork and shift the registration to an appropriate audio system, whichis useful.

What is claimed is:
 1. A communication system comprising: a plurality ofunit communication systems each having a control terminal device and oneor more communication devices which are connected by a network, wherein:the control terminal device comprises a communication circuit configuredto communicate with the one or more communication devices through thenetwork or by direct connection, the control terminal device isconfigured to transmit a network connection preparation command to thecommunication device in the unit communication system to which thecontrol terminal device belongs when a communication device is added tothe unit communication system to which the control terminal devicebelongs, the communication device comprises: a communication circuitconfigured to communicate with the control terminal device through thenetwork or by direct connection, and an operation portion configured toaccept an operation of connection to the communication system, and whenthe operation portion accepts the operation of connection, thecommunication device is configured to directly connect to the controlterminal device that transmits the network connection preparationcommand and to obtain information for connecting to the network of theunit communication system in a case that the communication circuit ofthe communication device is not connected to the network or in a casethat the network connection preparation command is not received althoughthe communication circuit of the communication device is connected tothe network.
 2. The communication system according to claim 1, wherein:the communication device is an audio device.